1. Technical Field
The present invention relates generally to an improved data processing system, and in particular, to a method and apparatus for processing data. Still more particularly, the present invention provides a method and apparatus for processing outgoing Internet protocol packets.
2. Description of Related Art
The Internet, also referred to as an “internetwork”, is a set of computer networks, possibly dissimilar, joined together by means of gateways that handle data transfer and the conversion of messages from a protocol of the sending network to a protocol used by the receiving network. When capitalized, the term “Internet” refers to the collection of networks and gateways that use the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of protocols.
Currently, the most commonly employed method of transferring data over the Internet is to employ the World Wide Web environment, also called simply “the Web”. Other Internet resources exist for transferring information, such as File Transfer Protocol (FTP) and Gopher, but have not achieved the popularity of the Web. In the Web environment, servers and clients effect data transaction using the Hypertext Transfer Protocol (HTTP), a known protocol for handling the transfer of various data files (e.g., text, still graphic images, audio, motion video, etc.). The information in various data files is formatted for presentation to a user by a standard page description language, the Hypertext Markup Language (HTML). In addition to basic presentation formatting, HTML allows developers to specify “links” to other Web resources identified by a Uniform Resource Locator (URL). A URL is a special syntax identifier defining a communications path to specific information. Each logical block of information accessible to a client, called a “page” or a “Web page”, is identified by a URL. The URL provides a universal, consistent method for finding and accessing this information, not necessarily for the user, but mostly for the user's Web “browser”. A browser is a program capable of submitting a request for information identified by an identifier, such as, for example, a URL.
The protocol used in transferring data over the Internet is called Transmission Control Protocol/Internet Protocol (TCP/IP). TCP provides transport functions, which ensures that the total amount of bytes sent is received correctly at the other end. TCP/IP is a routable protocol, and the IP part of TCP/IP provides this capability. In a routable protocol, all messages contain not only the address of the destination station, but the address of a destination network. This allows TCP/IP messages to be sent to multiple networks (subnets) within an organization or around the world, hence its use in the worldwide Internet. Every client and server in a TCP/IP network requires an IP address, which is either permanently assigned or dynamically assigned at startup. This protocol is also often used in other types of network data processing systems, such as, local area networks, wide area networks, and intranets, to direct messages between different data processing systems or nodes.
In some cases, messages may be broadcast to everyone on a network or network segment. These types of messages are also referred to as “broadcast traffic”. In a network, broadcast traffic is the message traffic that is sent out to everybody on a network segment. Broadcasts are issued for address resolution when the location of a user or server is not known. This type of traffic may occur, for example, when clients and servers come online and identify themselves. Sometimes, network devices continually announce their presence. In all cases, the broadcast has to reach all possible networks and stations that might potentially respond.
Currently, the processing of packets to verify whether the destination IP address is a broadcast address occurs with every outgoing packet. Some of the steps involved in verifying whether a destination IP address is a broadcast address are expensive with respect to resources in a data processing system. Typically, the process involves checking to see whether the destination IP address is one of a set of different kinds of broadcast addresses, such as, for example, 255.255.255.255 or 0.0.0.0. Another check made is to determine whether the destination IP address is a subnet broadcast address, such as, for example, addresses in which the host part of the address is all zeros. The processing in which checks are made to see whether a destination IP address is a subnet broadcast address becomes expensive with respect to resources in a data processing system when the outgoing interface contains many IP aliases. Further, on a multiprocessor system, a lock on the interface is often required to perform the verification steps. In other words, all outgoing traffic must wait for the interface to be released before other packets can be verified. This lock may form a bottleneck for pseudo devices such as an Ether channel in which multiple adapters are assigned to a single IP interface.
Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for processing outgoing IP packets in a data processing system.